Osprey description

Occurring on every continent except Antarctica, the osprey is the one of the most widespread birds of prey. The plumage of the osprey is generally brown above and white below, with a whitish head and a dark stripe through each eye (2)(4). The wings are long and pointed and the legs are stout and heavily scaled (4). Also known as the fish hawk, the osprey exhibits several adaptations to hunting and eating fish, including dense, oily plumage, large feet, scaly soles, and a reversible outer toe that helps with carrying fish through the air (2)(4). The juvenile is fairly similar to the adult but the head is more darkly-streaked and the upperparts appear scaled with cream and pale rufous (4). There are four subspecies of the osprey, each occupying a different part of its overall range and differing slightly in size and appearance: Pandion haliaetus haliaetus, P. h. carolinensis, P. h. cristatus and P. h. ridgwayi(4)(5).

Related species

Osprey biology

The osprey forages almost exclusively for live fish, with other prey such as small mammals, injured birds, reptiles, amphibians and crustaceans forming only a very minor part of its diet (4)(5)(6). Hovering or circling at moderate height, it plunges down feet first to snatch fish from the water’s surface, sometimes even completely submerging in the process (2)(5). Carrying its captured prey with its long talons, it alights on an open perch or a patch of bare ground, where the catch is consumed piecemeal (4)(5).

Although usually seen singly or in pairs, in some parts of its range the osprey is loosely colonial (4)(5). During the breeding season, pairs form at the nest site following a dramatic courtship display. The main display involves the male flying slowly over the nest site giving screaming calls, whilst clasping fish or nesting material (4)(6). The large stick nest is built near the ground or high up in a tree, or on a cliff, rocky outcrop, telephone pole, dilapidated building, or even just on the ground (4)(5). The clutch size is usually around two to four eggs, which are incubated largely by the female over 35 to 38 days (5). Once hatched, the female broods and feeds the chicks, whilst the male forages for food to bring back to the nest (5). The young fledge at around a month and a half to two months old, but remain dependent on the parents birds for another two to three months, after which they disperse widely (4)(5).

Aside from sedentary populations in Australia, the Caribbean, north Africa, and the Mediterranean basin, the osprey is highly migratory (5). After the breeding season, northern populations usually venture south, often travelling large distances across the equator, where they remain for the austral summer (4)(5).

Osprey range

The combined range of the four osprey subspecies is colossal (2)(4)(5). Pandion haliaetus haliaetus breeds in Europe, Asia and north Africa and winters in South Africa, India and southeast Asia; P. h. carolinensis breeds in North America and the Caribbean and winters in Florida, the Caribbean and South America; P. h. cristatus is a year round resident of coastal Australia and the southwest Pacific; and P. h. ridgwayi inhabits the Caribbean, from Cuba and the Bahamas to southeast Mexico and Belize (5)(6)(7).

Species with a similar range

Osprey habitat

The Osprey is typically found near still or slow-flowing water, including both salt water and fresh water, and thus occurs in a wide variety of habitats such as lakes, rivers, wooded swamps with open water, and shorelines, from cliffs to salt-flats (4)(5).

Osprey status

Osprey threats

From the 18th century to the mid 20th century, the osprey was widely persecuted by humans, particularly in Europe, whilst during the 1950s and 1960s there were dramatic declines due to pesticide pollution, especially in North America. Fortunately, the osprey still has a massive global population which now appears to be increasing again in many regions (4)(5).

Authentication

Glossary

Amphibians

Cold-blooded vertebrates of the class Amphibia, such as frogs or salamanders, which characteristically hatch as aquatic larvae with gills. The larvae then transform into adults with air-breathing lungs.

Crustaceans

Diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.

Incubated

The act of keeping eggs warm so that development is possible.

Subspecies

A population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.

Embed this ARKive thumbnail link ("portlet") by copying and pasting the code below.

Terms of Use - The displayed portlet may be used as a link from your website to ARKive's online content for private, scientific, conservation or educational purposes only. It may NOT be used within Apps.